Abstract: Laser shock processing is a technology of using high-power pulsed laser to realize new surface modification of metal materials. Three metallic materials, aluminum, titanium and stainless steel are studied under laser shock processing in the case of water bound marker coating layer and a protective layer scribbled by a marker pen. The damage properties of the three metallic materials and the relation of the depth of the pit on the metal samples and the numbers of pulsed laser impacts are demonstrated. The analysis results show that the depth and the numbers of pulsed laser impacts are in the linear relationship and the slope is related to the yield strength of the metal materials. Furthermore, to investigate the influence of different shapes of the focused spot, experiments with the laser shock using a circular spot and a rectangular spot are made.

Key words: diffractive optical element